Wernette, Philip
Macmillan, 1955
Buku Teks
Krooss, Herman Edward, 1912-1975, author
Prentice-Hall, 1955
Buku Teks
edited by Harold F. Williamson
Prentice-Hall, 1951
Buku Teks
Robertson, Ross M., author
Harcourt, Brace & World, 1964
Buku Teks
Davies, J. Kenneth, 1925-, author
J.B. Lippincott, 1970
Buku Teks